ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

Showing 1-5 of 18 Abstracts search results

Document: 

SP143-01

Date: 

May 1, 1994

Author(s):

M. H. Maher, B. Chen, J. D. Prohaska, E. G. Nawy, and E. Snitzer

Publication:

Symposium Papers

Volume:

143

Abstract:

A novel fiber optic sensor was tested on reinforced concrete beams with the objective of monitoring strain due to flexural deformations. A fiber optic Bragg grating (FOBG) sensor, developed recently at the United Technologies Research Center (UTRC) for monitoring of strain in structural composites, was used. The FOBG sensor was tested in beam models to measure load-induced strain. Results showed that the FOBG sensor can be accurately and effectively used to monitor strain for both existing and new concrete structures. A number of issues, such as sensor bonding to the structural component, sensor placement, and practical instrumentation techniques, were addressed in this study.

DOI:

10.14359/4579


Document: 

SP143-02

Date: 

May 1, 1994

Author(s):

V. Sharma, W. L. Gamble, J. Choros, and A. J. Reinschmidt

Publication:

Symposium Papers

Volume:

143

Abstract:

Load tests were conducted on three recently constructed precast pretensioned concrete railroad bridges. The three bridges tested were instrumented at their centerline of span with concrete strain gages applied to appropriate locations to quantify the bridge behavior and to obtain impact factors. A dedicated test train was used to apply the loading for all the measurements. This train consisted of two locomotives followed by 10 freight cars representative of most common types of cars used in modern freight trains. The test trains had a total gross weight of 1250 tons and a length of 1400 ft and included five platform-type intermodal cars, 89-ft flat cars (TOFC/COFC), and also hopper and box cars. The test train was operated at speeds of up to 70 mph. Paper describes the bridges tested, with special emphasis on field testing techniques and the personal computer-based data acquisition system.

DOI:

10.14359/4580


Document: 

SP143-07

Date: 

May 1, 1994

Author(s):

A. Carpinteri, S. Valente, G. Ferrara, and L. Imperato

Publication:

Symposium Papers

Volume:

143

Abstract:

Two small-scale 1:40 models of a gravity dam are subjected to equivalent hydraulic and weight loading. An initial notch in the upstream wall propagates during the loading process toward the foundation. Crack mouth opening control is performed, and the load-versus-CMOD diagram is plotted. A numerical simulation of the experiments is carried out using a cohesive fracture model in mixed mode condition. The structural behavior of the models and the crack trajectories are reproduced by the finite element idealization in a satisfactory way. The experiments described in this paper, while adopting the physical modeling techniques for civil structures, would be better defined as an example of the application of an experimental technique for assessing structural and material performance of concrete rather than rigorous physical modeling.

DOI:

10.14359/4582


Document: 

SP143-09

Date: 

May 1, 1994

Author(s):

R. Y. Miao and W. H. Yang

Publication:

Symposium Papers

Volume:

143

Abstract:

The interface confining stress between steel tube and core concrete is an important problem in the analysis of the behavior of concrete-filled steel tubes. However, no satisfactory experimental method to measure the interface stress directly has been developed because of the peculiar geometry of concrete-filled steel tubes. In this study, the significance of measuring interface stress is discussed, and the use of hydraulic analogy, or analogous hydraulically loaded control specimens, is introduced. In this paper, the fundamental mechanism, instrumentation, and procedure of hydraulic analogy will be described in detail together with examples.

DOI:

10.14359/4583


Document: 

SP143-10

Date: 

May 1, 1994

Author(s):

M. Wecharatana and A. P. Ranasinghe

Publication:

Symposium Papers

Volume:

143

Abstract:

The break-off test is a recently developed nondestructive test for concrete. Although many experimental investigations have been carried out on this test, no in-depth theoretical evaluation has been done. In this study, the behavior of the break-off test specimen is investigated, and the theoretical basis of the test is explored. Based on linear elastic fracture mechanics, a model to predict the strength-manometer reading relationship of the test is proposed and compared with experimental results with good correlation. It was found that the ACI recommendation on the modulus of rupture (MOR) may be very conservative for certain members. The MOR of a rectangular beam is different from that observed from a circular cross section, such as the break-off test specimen. New MOR values are suggested for small rectangular beams and members with circular cross sections.

DOI:

10.14359/4584


1234

Results Per Page